Log Reader error: 'Could not load file or assembly 'LogReader.SqlServer.SLS' (4378255)

There is an error with the LogReader in Toad for SQL Sever v8.1 (and also seen in 8.0), where it is not possible to read transaction log files, as the following error appears at the moment of trying to read the log file:

''Could not load file or assembly 'LogReader.SQLServer.SLS,
Version=8.9.1.310, Culture=neutral,
PublicKeyToken=c862883b2ae69822' or one of its dependencies.
An attempt was made to load a program with an incorrect format.'

The steps to replicate:
- Connect to DB
- Open Tools | Administer | LogReader
- Choose 'Online Transaction Log' click next
- Select Instance and DB, click next
- Select transaction log backup file, click next
- The error appears

WORKAROUND:
None

STATUS:
Waiting for fix in a future release of Toad for SQL Server